JPS5983639A - Manufacture of square bottom bag made of synthetic resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method of manufacturing a square bottom bag made of synthetic resin.

More specifically, the present invention relates to a method for continuously manufacturing a square bottom bag made of synthetic resin in which a bottom plate is joined to the square bottom portion.

Bags made of synthetic resin (plastic film) are water resistant,
They are superior to paper bags in various aspects such as mechanical strength and surface gloss, and are therefore used for a wide range of purposes. However, since synthetic resin bags generally have a weak film, they do not have sufficient independence when storing articles or stability when placed on the bag after storing articles. As an improvement on this point, it is already known that the entire bag is made of relatively thick paper with a synthetic resin layer laminated on the surface, but such bags are expensive. I had no choice but to do it. There are also already known bags that have a reinforcing bottom plate made of cardboard or resin sheet attached to the bottom of the bag.
Such bags require a step of attaching the bottom plate with an adhesive, and this attaching step requires a great deal of labor and time. Moreover, resin films such as polyethylene have poor adhesive properties, and there are restrictions on the adhesives that can be used, which also leads to an increase in manufacturing costs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently manufacturing a synthetic resin square-bottomed bag having a bottom plate joined to its square bottom.

The present invention provides a cutting process for cutting a gusseted flat cylindrical film into a predetermined length, a bottom welding part forming process for welding the flat cylindrical film in the width direction to form a bottom welded part, and a bottom welding part forming process for welding the flat cylindrical film in the width direction. A core holding the bottom plate is inserted on the tip side into the flat cylindrical film in which the welded portion is formed, and the bottom plate is rotated near the bottom welded portion by rotating the tip side of the core described in 11J. a corner bottom forming step in which a corner bottom is formed by pressing the inner Ill K bottom plate; a bottom plate joining step in which the bottom plate is joined to the corner bottom by pressing a heater from the outside of the corner bottom against which the inner Ill K bottom plate is in contact; and after the bottom plate joining step. The above object is achieved by providing a core extraction step of releasing the bottom plate from the tip side of the core and then extracting the core from within the cylindrical film.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 schematically shows the overall configuration of a manufacturing apparatus to which an embodiment of the method for manufacturing square bottom bags made of synthetic resin according to the present invention is applied. The flat cylindrical film 2 is wound up in many layers. The flat cylindrical film 2 is made of synthetic resin, and is particularly preferably a soft synthetic resin such as polyethylene or polyzolopyrene. The thickness of the flat cylindrical film 2 is variously selected depending on the purpose, size, etc. of the square bottom bag to be manufactured, but is usually 10 μm to 20 μm.
It is about 0 pm.

A flat cylindrical film 2 fed from a raw film 1 is suspended between a pair of presser plates 5 via transfer rollers 3 and 4 consisting of a pair of roller bodies. The holding plates 5 are arranged opposite to each other so as to sandwich the film 2 in the width direction from both sides of the flat cylindrical film 20,
It is attached via a biasing means to a reciprocating member 6 that moves forward and backward toward the film 2 from both sides of the film 20. A cutter γ is provided near the bottom of the presser plate 50 of the advancing/retracting member 6 in the figure, and a heat sealer 8 is provided further below and near the cutter 7, so that the advancing/retracting member 6 advances toward the flat cylindrical film 2 When the film 2 is held between both sides, the flat cylindrical film 2 is held and fixed from both sides by the holding plates 5 and cut by the trap and cutter 1 in the width direction.

[1. Welded in the width direction by the heat sealer 8.

That is, the flat cylindrical film 2 is cut by r+I from the cutter IK.
A cutting process is performed to cut L;l to a certain length, and -! ,
Ta.

A bottom welded portion forming step is performed in which the flat cylindrical film 2 is welded in the width direction using the Schiff Q to form the bottom welded portion 11.

The bag member 12 is made of a flat cylindrical film 2 that has been cut in the width direction by a cutter I and has a bottom welded part 11 formed thereon.
The core 21 is inserted into the bag member 12 while hanging down due to its own weight or by a transport means (not shown). A plurality of cores 21 are arranged radially along the circumferential direction of the rotating mechanism 22.
2 to Nakasho? It is configured to be rotated sequentially in the counterclockwise direction in FIG. 1.

As shown in FIG. 2, the tip end side of the core 21 has a rotary disk 23 formed in a substantially thick-walled hollow rectangular disk shape, and the rotary disks 23 are arranged parallel to each other. It is rotatably supported on the distal end sides of the two support rods 24 via supports @25.

The rotary plate 23 is composed of a suction portion 26° with the support shaft 25 provided on both ends thereof, and a blow-off portion 27 disposed on the tip edge side of the suction portion 26. and have independent hollow portions that are not communicated with each other.

Further, as shown in FIG. 3, one side of the suction portion 26 and the blow-off portion 27 form the same plane, and a plurality of suction holes 28 are bored in the surface of the suction portion 26. There is. Further, the other end of a flexible tube 29 connected to one end of a suction mechanism (not shown) is communicated with the suction section 26, and the suction mechanism causes one side of the rotary plate 23 to be connected to a bottom plate 31. is adsorbed and held in a removable manner. Here, the material of the bottom plate 31 is as follows:
Examples include cardboard, thermoplastic resin sheets, etc. When cardboard is used, it is preferable to use one whose surface is coated with a resin such as polyethylene in order to easily bond to the bag member 12. Also, 11 of the bottom plate 31? The length can be selected depending on the application, but it is usually about 1.1 to 2 tttn.

[) 1. There is a recess i′ at approximately the center position on one end edge side of the suction portion 26.
lI< 33 is formed, and a rotation shaft 34 is housed in this recess 33. A timing spool 35 having a substantially gear-shaped cross section is fitted and fixed on the rotation shaft 34. An endless timing belt 36 is hooked and rotated. The rotation shaft 34 is disposed on the same straight line as the support shaft 25, and a driving source (not shown) such as a sliding motor is connected to the lower end side of the timing belt 36 in FIG. By driving the timing belt 36 in the forward and reverse directions by the drive source, the one-turn disc 23 is configured to be appropriately rotated on the distal end side of the support rod 24.

Further, a blowing hole 37 is provided at the upper edge of the blowing portion 2T in FIG. 2, and the blowing portion 27 has one end (
A 111K air supply mechanism (not shown) is connected to the other end of the connected flexible tube 38, and air is supplied from the air supply mechanism into the blow-off section 27 via the flexible tube 38. Then, air is blown out from the blowing hole 37.

When inserting the core 21 into the bag member 12, the bottom plate supply mechanism 81 ( 1st
The upper half of the bottom plate 31 (see figure) is adsorbed, and at this time, the bag member 12 is opened and inserted smoothly by blowing out air from the blow-off hole 3T. Note that when the bag member 12 is opened by blowing air from the blow-off hole 37, the bag member 12
A holding member is placed near the outside of the opening, or
The opening may be assisted by suction means or the like.

After inserting the core 21 so as to reach the bottom welded portion 11 of the bag member 12, the timing belt 36 is rotated to rotate the bottom plate 31 in the vicinity of the bottom welded portion WJ11 of the bag member 12. Rotating plate 23 is supported by rod 2
4, in other words, the bottom plate 31
is rotated to a vertical position in the vicinity of the bottom welded portion 11 to form the square bottom portion 41 (see each diagram).Here, the square bottom forming step is performed. Further, the bottom plate 31 is brought into contact with the inside of the formed corner J= portion 41.

When rotating the rotary disk 23 at the tip f111 of the core 21, the blowing hole 37 is closed while the bottom welded portion 11 side of the bag member 12 is substantially closed W1 by the holding rollers 45 and 46.
Air is blown into the bag member 12 in an equivalent amount. As a result, the bag f (dj, bag 12
In this case, even though both ends are jet-folded, the turning operation of the turning plate 23 and the bottom plate 31 in the vicinity of the bottom welded part 11 is performed smoothly, and therefore the square bottom part 41 is reliably formed. It will be done.

As shown in FIG. 3, the rotating shaft 51 of the holding roller 46 is rotatably supported by support rods 52 arranged parallel to each other, and the rotating shaft 51 has a rotation shaft 52 arranged parallel to each other. One end side of each moving rod 53 is rotatably supported. A rectangular plate-shaped presser plate 54 is attached to the tip of the rotating rod 53.
The -(Ill # side is supported by the rotating i7J function.

The holding plate 54 is moved counterclockwise 1■ in the figure by a coil spring 55.
1] and also.

One end side of the operating wire 56 is fixed to a predetermined position of the rotating end of the holding plate 540, and this operating wire 5
By appropriately pulling 6, the presser plate 54 is attached to the rotating rod 5.
The distal end side of the coil spring 3 is configured to be rotated according to the urging force of the coil spring 55 or against the urging force.

After the bottom plate 31 is rotated by the rotating disk 23 to form the square bottom part 41, the presser plate 54 is placed on the back surface of the bottom plate 31 on the side that is not attracted by the suction part 26. When placing the presser plate 54, the presser plate 54 is held perpendicular to the rotary rod 53, and the rotary rod 53 is rotated by a rotation mechanism (not shown) so that the rotary rod 53 is connected to the support rod 24. so that they are parallel to each other. In this state, approximately half of the back side of the presser plate 50 is supported by the suction portion 26, and the other approximately half is supported by the presser plate 54. Therefore, in this state, a flat heating portion is provided. By pressing the heater 61 against the corner bottom 41 from the outside of the bag member 12,
The bottom plate 31 is joined to the square bottom portion 41 by thermally welding the bottom plate 31 to each other. At this point, a bottom plate bonding step will be performed. In addition, the corner bottom part 41 and the bottom plate 3
1 may be joined by heat welding in one row over the entire surface of the bottom plate 31, or may be joined by welding in a line of a predetermined shape. However, the heating temperature of the heater 61 is usually around 150°C to 250°C, although it depends on the material and thickness of the bag member 12 and the bottom plate 31, and the state of joining.

In this way, the square bottom bag 100 is formed.

After joining the bottom plate 31 to the square bottom part 41, the turning plate 23 is rotated clockwise in FIG. 54 is rotated in the same direction as the rotary plate 23. As a result, the corner bottom portion 41 to which the bottom plate 31 is joined is folded.

During or after the folding operation of the corner bottom portion 41, the folding roller 7 consisting of a pair of roller bodies is
1 to clamp the corner bottom 41 (see FIG. 1).

Further, in a state where the corner bottom portion 41 is folded to some extent, the bottom plate 31 is released from the rotary plate 23, and the folded corner bottom portion is folded by the folding roller 71, as shown in FIG. 41 and hold the square bottom bag 100, thereby pulling out the square bottom bag 100 from the core 21. At this point, a core extraction step is performed to extract the square bottom bag 100 from the core 21. Note that when the square bottom bag 100 is removed from the core 21, the presser plate 54 is rotated clockwise during the fourth factor, so the presser plate 54 is rotated in the folded square bottom portion 4.
There is no risk of getting caught in 1. Furthermore, the extraction may be performed while blowing out air from the blow-off hole 37 of the rotary plate 23.

The square bottom bags 100 extracted from the core 21 are sequentially stocked on the stock table 72 as shown in FIG.
The bottom plate 31 is supplied again from 1.

According to this one-piece embodiment, the insertion of the bottom plate 31 into the bag member 12 and the formation of the square bottom portion 41 by rotation of the bottom plate 31 are performed by one core 21, and the core 21 is The square bottom portion 4 also serves as a receiving plate when the bottom plate 31 and the square bottom portion 41 are joined by the welding heater 61.
There is an effect that the square bottom bag 100 made of synthetic resin with the bottom plate 31 bonded to the bottom plate 1 can be efficiently manufactured.

Further, since the square bottom portion 41 is removed from the core 21 in a folded and twisted state by the folding roller 71, the square bottom bags 100 are manufactured one after another with the square bottom portion 41 folded and twisted. Therefore, it is extremely convenient to stock the square bottom bags 100.

Unfortunately, since the bottom plate 31 is welded to the corner bottom 41, the adhesion of the bottom plate 31 is faster compared to, for example, a conventional bottom plate made of cardboard or the like that is affixed to the corner bottom using an adhesive. It has the effect of stabilizing quality.

In this implementation, it was assumed that the bottom plate 31 was detachably held on the rotating plate 23 by suction means, but the rotating plate 23 could be attached to the rotating plate 23 by, for example, operating a claw member or the like that detachably holds both ends of the bottom plate 31. The bottom plate 31 may be retained. However, if a suction mechanism is used, the structure of the single rotation plate 23 can be made simpler, and there is no risk of damaging the film surface of the bag member 12.

Moreover, when inserting the bag member 12 into the core 21, air is blown from the blow-off hole 37 of the blow-off part 27, but blowing out of air is not necessarily necessary. However, if air is blown out as described above, the bag member 12 can be opened easily and the core 21 can be easily moved into the bag member 12. In addition, bag member 1
Rotate the rotary plate 23 on the bottom side of the bag 2 to open the square bottom 1.
1 is also performed while blowing out air from the blowing hole 3γ, but it is not necessarily necessary to rotate the rotary plate 23 while blowing out air, but by blowing out air, The square bottom portion 41 can be formed by rotating the bottom plate 31 easily by rotating the rotating plate 23 without causing wrinkles or the like on the bag member 12.

Although the presser plate 54 is not necessarily required, the heater 61 connects the bottom plate 31 and the square bottom portion 41 rather than providing the presser plate 54! The strength of the receiving part at the filter edge can be ensured, and the bottom plate 31 and the square bottom part 41 can be joined more reliably in diameter. In addition, in the embodiment described above, the square bottom i'1 (41) was extracted from the core 21 while being folded by the folding roller T1. 12 may be taken out.However, if you take it out after folding it, it is convenient to stock the square bottom bag 100 with 41 pieces.

As described above, according to the present invention, it is possible to efficiently manufacture a square bottom bag made of synthetic resin with a bottom plate joined to the square bottom portion.

[Brief explanation of drawings]

FIG. 1 is a front view showing the overall configuration of a manufacturing apparatus to which an embodiment of the method for manufacturing synthetic resin river bottom bags according to the present invention is applied;
2 to 4 are enlarged perspective views showing the operating states of the main parts of the manufacturing apparatus. 7゛°゛ cutter, 8゛° heat sealer, 11...° bottom welded part, 12... bag member, 21... core, 22...
・Rotation mechanism, 23... Turning plate, 31... Bottom plate, 41
...Square bottom, 45.46...Holding roller, 54...
・Press plate, 61... Heater, 71... Folding roller,
100... Square bottom bag. Agent Patent attorney Minoru Kinoshita (and 1 other person) Figure 1 197- Figure 2 3LA Figure 4

Claims (1)

[Claims] (1) A cutting process in which the gusseted flat cylindrical film is cut into a predetermined length, and a bottom welding process in which the flat cylindrical film is welded in the middle direction to form a bottom welded part. The bottom plate is formed by forming the bottom plate ([(4-cylindrical fin, holding the bottom plate on the tip side inside the bottom plate).
11 people rotate the tip side of the core to rotate the bottom plate 111
1. Form a square bottom by rotating near the attachment part of I8.
- Rotttqr corner shape 11 step, press a heater from the outside of the corner bottom with the bottom plate in contact with the corner j
a bottom plate joining step of joining the bottom plate of No. 1111 to the pad 5 part;
The synthetic resin is characterized in that, after the bottom plate 1λ is aligned, the bottom plate is released from the tip side of the core and the core is pulled out from inside the cylindrical film. 11'if l"! IJI4 manufacturing method of f'4 bottom bag.